计及分布式电源出力和负荷不确定性的配电网孤岛划分

针对计及分布式电源(DG)出力波动性及负荷需求不确定性的配电网孤岛划分问题,提出了一种基于树背包理论的最优孤岛划分新模型及相应求解方法。所述方法的基本思路为:首先,构造了DG出力波动性和负荷需求不确定性基于树背包理论的随机最优孤岛划分新模型;进而,基于拉丁超立方超样方法、确定性树背包算法、数理统计方法,确定各初始孤岛的组成,包括DG及相应负荷节点;最后,对每个初始孤岛在考虑孤岛重构的基础上采用基于随机最优潮流的优化调整,通过优化调整而保证DG孤岛运行的最优性、安全性和经济性。所述方法实现了计及分布式发电及负荷出力不确定性情况下最佳孤岛的系统形成方法,能根据实时情况确定最大可能出现的孤岛,相对于在确定性条件下的孤岛具有更强的可信度。含有多个DG的PGE 69节点系统的算例验证了所述模型及算法的有效性。

Island Partition of Distribution Network Considering Uncertainty of Distributed Generators and Loads

For the island partition of distribution network considering the output fluctuation of distributed generators (DG) and load uncertainty, a new optimal island partition model and its solving method are presented based on tree knapsack problems (TKP). The basic idea of the paper is first, a new stochastic island partition model considering the uncertainty of DGs and loads is developed. Then the Latin hypercube sample method, the deterministic tree knapsack algorithm and mathematical statistics method are adopted to determine the composition of the initial island, including DGs and loads. Finally, for each initial island, the stochastic optimal power flow is used to optimize and adjust the initial island on the basis of island reconfiguration. Through the above optimization and adjustment, the security, optimization and economy for each DG island operation are ensured. The method has achieved optimal islanding under the uncertainty of DGs and loads, the islands most likely to appear according to the real-time situation, which has a stronger credibility compared with the condition of certainty. The results of an PG&E 69-bus distribution system with several DGs show the validity of the proposed model and method. This work is supported by National Natural Science Foundation of China (No. 51177107).